Product counterfeiting has a negative effect on many industries, but is potentially lethal to manufacturers of medical devices. This exclusive article showcases one technology that offers a solution to companies attempting to combat this growing problem by securing the identity of their products.

AT A GLANCE

A comparison of a human hair and a bi-component (two-tone) microtag. The hair is 100 microns in diameter and the microtag is 75 microns in diameter.

 Counterfeiting costs

 Brand concerns

 Product safety

 Microscopic solution

By Peter D. GabrieleIf you're from Texas, then life is all about "big." But if you are trying to protect your branded product from being counterfeited, you might want to think smallreally small. In fact, you might want to consider things that, in relative terms, are about three-quarters of the diameter of a human hair.

Economic Consequences

In 2004, the global effects of counterfeiting cost legitimate companies $600 billion,1 with an estimated $240 billion in the U.S. alone.2 For example, eight to ten percent of U.S. prescription pharmaceuticals representing ~$50 billion are thought to be counterfeit and one in five medications in Great Britain is thought to be fake.3 In addition to pharmaceuticals, more counterfeit medical devices, both finished goods and parts, are also appearing in the marketplace. Typically, these are "look-alike" devices that appear authentic, but do not meet or perform to medical standards and include devices ranging from aortic pumps to mesh implants for hernia repairs, as well as diagnostic equipment, such as stethoscopes and testing systems.4

Despite closer scrutiny by government and industry, the counterfeiting of electrical products in North America is believed to have grown in recent years. Medical devices are not immune to counterfeiting. Batteries and integrated circuit technologies are commonly targeted products, as well as reagents and other important biochemical supplies that drive the utility of the device or diagnostic process. Generally, the greater the value of the device, the more likely the product is a target.5

Aside from compromising the safety of device users and patients, manufacturers are adversely affected by loss of sale and loss of reputation when counterfeit parts fail that have been branded with their company's trademark. Loss of brand value is an additional problem of counterfeit commercial devices. The loss of life associated with a device failure that can be traced back to a breach in the value chain of components or the outright manufacturing of fake devices can devastate a company's reputation.5 Brand protection and risk mitigation is critical to every medical device manufacturer. Many companies have elaborate brand protection strategies that include not only chain of custody of components, paperwork, and manufacturing data, but also close control of each position in the value chain as device handling passes through the economic system. The game is insidious. For example, international drug counterfeiting is expected to increase to 13% by the year 2010 versus a legitimate industry growth of only 7% in that same time frame.6 These economic consequences are not only measured in money but in quality of effective healthcare, homeland security, and peace of mind. The U.S. Food and Drug Administration has proposed that all caplets, tablets, and capsules be traceable within two years. This initiative demands the development and implementation of new technologies to mitigate the counterfeit risks.

Covert Microtags

Shape, form and feature position are all possible elements of encryption in a microtag.

One of these new technologies is a microscopic engineered marker technology or "microtag." This technology is based on a design strategy that involves content relevant features. They are intentionally designed inclusions that assist in the visualization of information. These features are not simple static symbols, but rather visual elements that support multivariate information like an arrangement of dots in a matrix or the relative position of symbol shapes to one another. Such symbolic relationships serve to create a microscopic cipher or encryption as visualized features within the microtag particle. The unique aspect of this technology is that the chemistry of the inclusions (shapes and designs) can be precisely engineered for both covert service and forensic analysis.

Multiple Levels of Information

All microtag designs are custom engineered to involve multiple levels of information within a single tag design. There is no standard format other than size. The microtag material can be derived from a host of materials, including food grade chemistries for situations where the tagged article is in direct human contact. In contrast, high-temperature engineering polymers can be used for exposure to hostile environments. Materials may also include ferromagnetic and ceramic materials for specialized applications on machined parts.

Size Counts

The human hair is about 100 microns in diameter. A strong anti-counterfeiting plan should include a layered application of covert and overt technologies. Covert microtags that are part of a layered technology approach are roughly 75 microns or three quarters the diameter of a human hair. Although these tags look like flattened microscopic debris, they are actually engineered to contain discrete information or relevant features that, when spatially resolved, lead to information visualization.

The purpose of the information bearing tag is to provide a method to covertly mark an article of commerce such that the article can be authenticated and the original article can be verified as the brand valued item. The tags are designed and customized materials of construction chosen to contain information that is unique to the service requirements or point of origin identity of the article.For example, the materials of construction that make up the microtag, such as the polymer or matrix materials, can be designed from pharmaceutical excipient polymers. Other material can also be placed into service on or within the tablet or capsule, such as a microtag derived from polylactic acid, which is biodegradable and edible. A system of tagging "inside and out" can serve as a non-destructive covert exterior marker or a forensic internal marker. In contrast, Ultem, an engineering polymer capable of surviving high temperature exposure, can be placed in service where articles are exposed to high temperatures. In addition, microtags can be designed to sinter, keeping a shape following exposure to direct flame.

Shape as a Code

Since RFID tags can be counterfeited, this microtag is marking an RFID providing verification that it is the original.

Increasing or decreasing the number or shape of the peripheral features will change the number of theoretical rays as well as the associated angle between rays. The designer can use his imagination when choosing a specific geometry to program a reader. These shapes and feature dimensions can be programmed into image recognition software such that the shape and features are recognized by a reader as valid. Because the sizes of these particles are below the resolution limits of the human eye, they are considered covert devices. Devices undetectable with normal vision require the aid of a hand held reader that is essentially a camera microscope.

Image Capture

The reader captures an image of the microtag. A reading that responds with a valid "OK" authenticates the commercial article.

Today, counterfeiters are sophisticated to the extent that manufacturers need multiple levels of protection. Overt technologies include color-shifting inked features, holograms, and bar codes, as well as package design features. Covert technologies are deliberately hidden from obvious detection. Covert technologies include microscopic particles as well as certain packaging technologies.

Multivariate Information

The microtags are unique in that they can include multivariate levels of information. A single tag design can carry several levels of identity. Geometry, as mentioned above, is one variant level. Content relevant dimensions that involve trigonometric and geometric spatial features are another level. For example, a geometric figure with precise internal angles can be "contained within" a design. This variant level of code is based on the spatial relationship of component features that are resolved by inclusions of shapes with different color or shape and fine structure.

Design Strategies

Design strategies can be both covert and forensic. Covert design strategies can be as simple as a single letter or initial on the microtag face or as complicated and sophisticated as possible to involve forensic analysis. For example, a design strategy that includes not only color as contained in a shape but frequency specific color assignments can be precisely read as spectrometric frequency values rather than arbitrary colors or shades.At first glance, this sounds complicated but it is rather straight forward photometric analysis. The absorption spectrum of the colorant used in the fabrication of design is frequency matched to the illuminating light source and detector band pass in the reader. So red is not just "red." If the red colorant has absorption maximum at 700 nM, and the illuminating source in the reader is matched to that absorption, the image is enhanced. Of course, the more sophisticated the approach, the more costly the components.Another option is to create features that are only detectable in specific frequency regions of the EM spectrum. For example, design a microtag such that all features are "readable" within a narrow band in the UV frequency region or similarly in the NIR.

An electron dispersive spectrum of a doped microtag (click here to enlarge).

A different design approach can involve elemental doping of the microtag polymer matrix with a specific composition of elements. An elemental composition can be buried within the polymer blend that forms the microtag. The microtag can then be forensically analyzed by electron dispersive spectroscopy (EDS). The EDS response will show the relative composition and identity of the elements as a tag "signature."

FT-IR imaging can identify the chemistry of multivariate composition (i.e. multi-component chemistry of the microtag through the resolution and spatial relationship of specific functional group chemistry that resides within the resolvable features of the microtag.) For example, FT-IR imaging can describe the spatial resolution of chemical functional groups within the polymer matrix of an included design structure and distinguish that structure from the surrounding matrix. In other words, the FT-IR image can resolve the location of chemically specific shapes from background. Here the polymer signature can act as a level of covert security.

Counterfeiting is a big business that only continues to grow in every industry. Medical device manufacturers need to adapt a method to combat this negative trend not only to protect profits, but also to secure brand identity and consumer confidence. Covert microtag technology is an area that offers one solution to this problem.

For additional information on the technologies and products discussed in this article, see Adhesives Research at www.adhesivesresearch.com.

Peter D. Gabriele is the technical director for ARmark Authentication Technologies at Adhesives Research, 400 Seaks Run Rd., Glen Rock, PA 17327. He earned both a bachelor's and master's degree in biochemistry from the University of Hartford and a master's degree in technology management from the University of Pennsylvania PENN Engineering and The Wharton School of Business. Gabriele holds several patents, has written numerous technical articles, and is a past recipient of the Roon Foundation Award and the Dahlquist Award. Adhesives Research is a manufacturer of custom pressure-sensitive adhesives and related products. More information is available at 800-445-6240 or pgabriele@arglobal.com.